Covered prosthetic heart valve

ABSTRACT

A prosthetic heart valve has a frame including a plurality of strut members, an inflow end, and an outflow end. A leaflet structure is situated at least partially within the frame, and a covering is disposed around an exterior of the frame. The covering includes a cushioning layer, and a first strip member folded over an inflow circumferential edge portion of the cushioning layer to form a first protective portion. A second strip member is folded over an outflow circumferential edge portion of the cushioning layer to form a second protective portion. The first strip member and the second strip member are spaced apart from each other along a longitudinal axis of the prosthetic heart valve.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.15/876,053, filed Jan. 19, 2018, which claims the benefit of U.S.Provisional Patent Application No. 62/535,724 filed on Jul. 21, 2017,U.S. Provisional Patent Application No. 62/520,703 filed on Jun. 16,2017, and U.S. Provisional Patent Application No. 62/449,320 filed onJan. 23, 2017. Each of U.S. application Ser. No. 15/876,053, U.S.Provisional Patent Application No. 62/535,724, U.S. Provisional PatentApplication No. 62/520,703, and U.S. Provisional Patent Application No.62/449,320 are incorporated herein by reference in their entirety.

FIELD

The present disclosure relates to prosthetic heart valves, and inparticular to prosthetic heart valves including a covering that cushionsthe tissue of a native heart valve in contact with the prosthetic heartvalve.

BACKGROUND

In a procedure to implant a transcatheter prosthetic heart valve, theprosthetic heart valve is typically positioned in the annulus of anative heart valve and expanded or allowed to expand to its functionalsize. In order to retain the prosthetic heart valve at the desiredlocation, the prosthetic heart valve may be larger than the diameter ofthe native valve annulus such that it applies force to the surroundingtissue in order to prevent the prosthetic heart valve from becomingdislodged. In other configurations, the prosthetic heart valve may beexpanded within a support structure that is located within the nativeannulus and configured to retain the prosthetic heart valve at aselected position with respect to the annulus. Over time, relativemotion of the prosthetic heart valve and tissue of the native heartvalve (e.g., native valve leaflets, chordae tendineae, etc.) in contactwith the prosthetic heart valve may cause damage to the tissue.Accordingly, there is a need for improvements to prosthetic heartvalves.

SUMMARY

Certain disclosed embodiments concern coverings for prosthetic heartvalves and methods of making and using the same. In a representativeembodiment, a prosthetic heart valve comprises a frame comprising aplurality of strut members, and having an inflow end and an outflow end.The prosthetic heart valve further comprises a leaflet structuresituated at least partially within the frame, and a covering disposedaround the frame. The covering comprises a first layer and a secondlayer, wherein the second layer has a plush surface. The first layer isfolded over a circumferential edge portion of the second layer to form aprotective portion that extends beyond the strut members in a directionalong a longitudinal axis of the prosthetic heart valve.

In some embodiments, the protective portion is a first protectiveportion located adjacent the inflow end of the frame, and the coveringfurther comprises a second protective portion located adjacent theoutflow end of the frame.

In some embodiments, the first layer extends along an interior surfaceof the second layer from the inflow end of the frame to the outflow endof the frame and is folded over a circumferential edge of the secondlayer at the outflow end of the frame to form the second protectiveportion.

In some embodiments, the first layer of the first protective portion isconfigured as a strip member that is folded over the circumferentialedge portion of the second layer at the inflow end of the frame.

In some embodiments, a first layer of the second protective portion isconfigured as a strip member that is folded over a circumferential edgeportion of the second layer at the outflow end of the frame.

In some embodiments, the strip member of the first protective portionencapsulates respective apices of the strut members at the inflow end ofthe frame, and the strip member of the second protective portionencapsulates respective apices of the strut members at the outflow endof the frame.

In some embodiments, the second layer comprises a fabric having a wovenlayer and a plush pile layer including a plurality of pile yarns.

In some embodiments, the pile yarns are arranged to form a looped pile,or cut to form a cut pile.

In some embodiments, the first layer comprises a tissue layer.

In another representative embodiment, a method comprises securing afirst layer to a first surface of a second layer such that alongitudinal edge portion of the first layer extends beyond alongitudinal edge portion of the second layer, the first surface of thesecond layer being a plush second surface. The method further comprisessecuring the attached first and second layers into a cylindrical shapeto form a covering, and situating the covering about a frame of aprosthetic heart valve, the frame comprising a plurality of strutmembers. The method further comprises folding the longitudinal edgeportion of the first layer over the longitudinal edge portion of thesecond layer to form a protective portion such that the protectiveportion extends beyond apices of the strut members in a direction alonga longitudinal axis of the valve.

In some embodiments, situating the covering about the frame furthercomprises situating the covering about the frame such that the plushfirst surface of the second layer is oriented radially outward.

In some embodiments, the protective portion is an inflow protectiveportion adjacent an inflow end of the frame, the first layer of theinflow protective portion is configured as a first strip member, and themethod further comprises folding a longitudinal edge portion of a secondstrip member over a longitudinal edge portion of the second layer toform an outflow protective portion adjacent an outflow end of the frame.

In some embodiments, folding the longitudinal edge portion of the firststrip member further comprises folding the longitudinal edge portion ofthe first strip member such that the inflow protective portionencapsulates respective apices of the strut members at the inflow end ofthe frame, and folding the longitudinal edge portion of the second stripmember further comprises folding the longitudinal edge portion of thesecond strip member such that the outflow protective portionencapsulates respective apices of the strut members at the outflow endof the frame.

In some embodiments, the second layer comprises a fabric having a wovenlayer and a plush pile layer including a plurality of pile yarns thatform the second surface.

In another representative embodiment, a method comprises positioning aprosthetic heart valve in an annulus of a native heart valve. Theprosthetic heart valve is in a radially compressed state, and has aframe including a plurality of strut members and having an inflow endand an outflow end. The prosthetic heart valve further comprises aleaflet structure situated at least partially within the frame, and acovering disposed around the frame. The covering comprises a first layerand a second layer. The second layer has a plush surface, and the firstlayer is folded over a circumferential edge portion of the second layerto form a protective portion that extends beyond the strut members in adirection along a longitudinal axis of the prosthetic heart valve. Themethod further comprises expanding the prosthetic heart valve in theannulus of the native heart valve such that the leaflet structure of theprosthetic heart valve regulates blood flow through the annulus.

In some embodiments, expanding the prosthetic heart valve furthercomprises expanding the prosthetic heart valve such that the protectiveportion prevents tissue of the native heart in contact with theprotective portion from contacting apices of the strut members.

In some embodiments, expanding the prosthetic heart valve furthercomprises expanding the prosthetic heart valve such that leaflets of thenative heart valve are captured between the plush surface of the secondlayer and an anchoring device positioned in the heart.

In some embodiments, the protective portion is a first protectiveportion located adjacent the inflow end of the frame, and the coveringfurther comprises a second protective portion located adjacent theoutflow end of the frame.

In some embodiments, the second layer comprises a fabric having a wovenlayer and a plush pile layer including a plurality of pile yarns thatform the plush surface.

In some embodiments, the first layer is folded over the circumferentialedge portion of the second layer such that the protective portionencapsulates respective apices of the strut members.

The foregoing and other objects, features, and advantages of thedisclosed technology will become more apparent from the followingdetailed description, which proceeds with reference to the accompanyingfigures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic cross-sectional view of a human heart.

FIG. 2 shows a schematic top view of a mitral valve annulus of a heart.

FIG. 3 is a perspective view of an embodiment of a prosthetic heartvalve.

FIG. 4A is a cross-sectional side view of a ring anchor deployed in amitral position of the heart, with an implanted valve prosthesis,according to one embodiment.

FIG. 4B illustrates a cross-sectional side view of a coil anchordeployed in the mitral position of the heart, with an implanted valveprosthesis, according to another embodiment.

FIG. 4C is a perspective view of a representative embodiment of ahelical anchor.

FIG. 5 is a perspective view of a prosthetic heart valve including arepresentative embodiment of a covering.

FIG. 6 is a side-elevation view of the prosthetic heart valve of FIG. 5.

FIG. 7 is a top plan view of the prosthetic heart valve of FIG. 5.

FIG. 8 is a cross-sectional side elevation view of the prosthetic heartvalve of FIG. 5.

FIG. 9 is a perspective view of a representative embodiment of acushioning layer including a plush pile.

FIG. 10 is a cross-sectional side view of the prosthetic heart valve ofFIG. 5 deployed in the mitral position of the heart.

FIG. 11 is a side elevation view of a prosthetic heart valve includinganother embodiment of a covering.

FIG. 12 is a perspective view of a backing layer, a stencil forproducing the backing layer, and a cushioning layer, before the backinglayer and the cushioning layer are secured together.

FIG. 13 is a cross-sectional side elevation view of a prosthetic heartvalve including another embodiment of a covering.

FIG. 14 is a detail view of an inflow protective portion of the coveringof FIG. 13.

FIG. 15 is a side elevation view of a prosthetic heart valve includinganother embodiment of a covering comprising a spacer fabric.

FIG. 16 is a perspective view of a representative embodiment of a spacercloth including looped pile yarns.

FIG. 17 is a side elevation view of the spacer fabric of FIG. 16.

FIG. 18 is a top plan view of an embodiment of a backing layer after itis cut using a parallelogram stencil.

FIG. 19 is a perspective view of a prosthetic heart valve includinganother embodiment of a covering.

FIG. 20 is a side elevation view of the prosthetic heart valve of FIG.19.

FIG. 21 is a plan view of an outflow end of the prosthetic heart valveof FIG. 19.

FIG. 22 is a cross-sectional side elevation view of the prosthetic heartvalve of FIG. 19.

FIG. 23 is a top plan view of the covering of FIG. 19 in an unfoldedconfiguration.

FIG. 24 is a perspective view illustrating placement of the prostheticheart valve of FIG. 19 into the covering after the covering is formedinto a cylindrical shape.

FIG. 25 is a perspective view of the inflow end of the prosthetic heartvalve of FIG. 19 illustrating attachment of the covering to the strutmembers of the valve frame.

FIG. 26 is a perspective view of the inflow end of the prosthetic heartvalve of FIG. 19 illustrating a strip member of the covering folded overthe strut members of the valve frame to form an inflow protectiveportion.

FIG. 27 is a perspective view of a frame for a prosthetic heart valveincluding another embodiment of a covering.

FIG. 28 is a cross-sectional side elevation view of the frame andcovering of FIG. 27.

FIGS. 29-31A are perspective views illustrating a representative methodof making the covering of FIG. 27.

FIG. 31B is a detail view of the electrospun layer of the inflow endportion of the covering of FIG. 31A.

FIG. 32 is a perspective view of a prosthetic heart valve including amain covering and a second covering extending over the apices of theframe.

FIG. 33 is a side elevation view of the prosthetic heart valve of FIG.32.

FIG. 34 is a plan view of a portion of the frame of the prosthetic valveof FIG. 32 in a laid-flat configuration.

FIG. 35 is a perspective view of the prosthetic heart valve of FIG. 32without the main outer covering.

FIG. 36 is a perspective view of the prosthetic heart valve of FIG. 32illustrating how the second covering is wrapped around the apices of theframe.

FIG. 37 is a perspective view illustrating the frame of the prostheticvalve of FIG. 32 including the second covering crimped onto a shaft of adelivery apparatus.

FIG. 38A is a side elevation view of the prosthetic valve of FIG. 19including an outer covering, according to another embodiment.

FIG. 38B is a detail view of the fabric of the outer covering of FIG.38A.

FIG. 39A is a plan view illustrating the prosthetic heart valve of FIG.38A crimped onto a shaft of a delivery device.

FIG. 39B is a detail view of the outer covering of the prosthetic heartvalve in FIG. 39A.

FIG. 40A is a cross-sectional side elevation view of the fabric of theouter covering of FIG. 38A in a relaxed state,

FIG. 40B is a cross-sectional side elevation view of the fabric of theouter covering of FIG. 38A in a tensioned state.

FIG. 41A is a plan view of another embodiment of a fabric outer coveringfor a prosthetic valve in a laid-flat configuration and including anouter surface defined by a pile layer.

FIG. 41B is a magnified view of the outer covering of FIG. 41A.

FIG. 42A is a plan view of a base layer of the outer covering of FIG.41A.

FIG. 42B is a magnified view of the base layer of FIG. 42A.

DETAILED DESCRIPTION

The present disclosure concerns embodiments of implantable prostheticheart valves and methods of making and using such devices. In oneaspect, a prosthetic heart valve includes an outer covering having abacking layer and a main cushioning layer disposed on the backing layersuch that the cushioning layer is oriented radially outward about thecircumference of the valve. The cushioning layer can be soft andcompliant in order to reduce damage to native tissues of the heart valveand/or of the surrounding anatomy at the implantation site due to, forexample, relative movement or friction between the prosthetic valve andthe tissue as the heart expands and contracts. The covering can alsoinclude an inflow protective portion and an outflow protective portionto cushion the surrounding anatomy and prevent the native tissue of theheart valve from contacting the apices of the strut members of theframe, thereby protecting the surrounding tissue. In another embodiment,the covering can include an inflow strip member and an outflow stripmember secured to the cushioning layer and folded over the apices of thestrut members to form the inflow and outflow protective portions.

Embodiments of the disclosed technology can be used in combination withvarious prosthetic heart valves configured for implantation at variouslocations within the heart. A representative example is a prostheticheart valve for replacing the function of the native mitral valve. FIGS.1 and 2 illustrate the mitral valve of the human heart. The mitral valvecontrols the flow of blood between the left atrium and the leftventricle. After the left atrium receives oxygenated blood from thelungs via the pulmonary veins, the mitral valve permits the flow of theoxygenated blood from the left atrium into the left ventricle. When theleft ventricle contracts, the oxygenated blood that was held in the leftventricle is delivered through the aortic valve and the aorta to therest of the body. Meanwhile, the mitral valve closes during ventricularcontraction to prevent any blood from flowing back into the left atrium.

When the left ventricle contracts, the blood pressure in the leftventricle increases substantially, which urges the mitral valve closed.Due to the large pressure differential between the left ventricle andthe left atrium during this time, a possibility of prolapse, or eversionof the leaflets of the mitral valve back into the atrium, arises. Aseries of chordae tendineae therefore connect the leaflets of the mitralvalve to papillary muscles located on the walls of the left ventricle,where both the chordae tendineae and the papillary muscles are tensionedduring ventricular contraction to hold the leaflets in the closedposition and to prevent them from extending back towards the leftatrium. This generally prevents backflow of oxygenated blood back intothe left atrium. The chordae tendineae are schematically illustrated inboth the heart cross-section of FIG. 1 and the top view of the mitralvalve of FIG. 2.

A general shape of the mitral valve and its leaflets as viewed from theleft atrium is shown in FIG. 2. Various complications of the mitralvalve can potentially cause fatal heart failure. One form of valvularheart disease is mitral valve leak or mitral regurgitation,characterized by abnormal leaking of blood from the left ventriclethrough the mitral valve back into the left atrium. This can be causedby, for example, dilation of the left ventricle, which can causeincomplete coaptation of the native mitral leaflets resulting in leakagethrough the valve. Mitral valve regurgitation can also be caused bydamage to the native leaflets. In these circumstances, it may bedesirable to repair the mitral valve, or to replace the functionality ofthe mitral valve with that of a prosthetic heart valve, such as atranscatheter heart valve.

Some transcatheter heart valves are designed to be radially crimped orcompressed to facilitate endovascular delivery to an implant site at apatient's heart. Once positioned at a native valve annulus, thereplacement valve is then expanded to an operational state, for example,by an expansion balloon, such that a leaflet structure of the prostheticheart valve regulates blood flow through the native valve annulus. Inother cases, the prosthetic valve can be mechanically expanded orradially self-expand from a compressed delivery state to the operationalstate under its own resiliency when released from a delivery sheath. Oneembodiment of a prosthetic heart valve is illustrated in FIG. 3. Atranscatheter heart valve with a valve profile similar to the prostheticvalve shown in FIG. 3 is the Edwards Lifesciences SAPIEN XT™ valve. Theprosthetic valve 1 in FIG. 3 has an inflow end 2 and an outflow end 3,includes a frame or stent 10, and a leaflet structure 20 supportedinside the frame 10. In some embodiments, a skirt 30 can be attached toan inner surface of the frame 10 to form a more suitable attachmentsurface for the valve leaflets of the leaflet structure 20.

The frame 10 can be made of any body-compatible expandable material thatpermits both crimping to a radially collapsed state and expansion backto the expanded functional state illustrated in FIG. 3. For example, inembodiments where the prosthetic valve is a self-expandable prostheticvalve that expands to its functional size under its own resiliency, theframe 10 can be made of Nitinol or another self-expanding material. Inother embodiments, the prosthetic valve can be a plastically expandablevalve that is expanded to its functional size by a balloon or anotherexpansion device, in which case the frame can be made of a plasticallyexpandable material, such as stainless steel or a cobalt chromium alloy.Other suitable materials can also be used.

The frame 10 can comprise an annular structure having a plurality ofvertically extending commissure attachment posts 11, which attach andhelp shape the leaflet structure 20 therein. Additional vertical postsor strut members 12, along with circumferentially extending strutmembers 13, help form the rest of the frame 10. The strut members 13 ofthe frame 10 zig-zag and form edged crown portions or apices 14 at theinflow and outflow ends 2, 3 of the valve 1. Furthermore, the attachmentposts 11 can also form edges at one or both ends of the frame 10.

In prosthetic valve 1, the skirt 30 is attached to an inner surface ofthe valve frame 10 via one or more threads 40, which generally wraparound to the outside of various struts 11, 12, 13 of the frame 10, asneeded. The skirt 30 provides a more substantive attachment surface forportions of the leaflet structure 20 positioned closer to the inflow end2 of the valve 1.

FIGS. 4A and 4B show side cross-sectional views of embodiments ofdifferent anchors that can be used to facilitate implantation of thevalve 1 at the mitral position of a patient's heart. As shown in FIGS.4A and 4B, a left side of a heart 80 includes a left atrium 82, a leftventricle 84, and a mitral valve 86 connecting the left atrium 82 andthe left ventricle 84. The mitral valve 86 includes anterior andposterior leaflets 88 that are connected to an inner wall of the leftventricle 84 via chordae tendineae 90 and papillary muscles 92.

In FIG. 4A, a first anchoring device includes a flexible ring or halo 60that surrounds the native leaflets 88 of the mitral valve 86 and/or thechordae tendineae 90. The ring 60 pinches or urges portions of theleaflets inwards, in order to form a more circular opening at the mitralposition, for more effective implantation of the prosthetic valve 1. Thevalve prosthesis 1 is retained in the native mitral valve annulus 86 bythe ring anchor 60, and can be delivered to the position shown, forexample, by positioning the valve 1 in the mitral annulus 86 while thevalve 1 is crimped, and then expanding the valve 1 once it is positionedas shown in FIG. 4A. Once expanded, the valve 1 pushes outwardly againstthe ring anchor 60 to secure the positions of both the valve 1 and thering anchor 60. In some embodiments, an undersized ring anchor 60 withan inner diameter that is slightly smaller than the diameter of theprosthetic valve 1 in its expanded state can be used, to providestronger friction between the parts, leading to more secure attachment.As can be seen in FIG. 4A, at least a portion of the native mitral valveleaflets 88 and/or a portion of the chordae tendineae 90 are pinched orsandwiched between the valve 1 and the ring anchor 60 to secure thecomponents to the native anatomy.

FIG. 4B is similar to FIG. 4A, except instead of a ring anchor 60, ahelical anchor 70 is utilized instead. The helical anchor 70 can includemore coils or turns than the ring anchor 60, and can extend bothupstream and downstream of the mitral valve annulus 86. The helicalanchor 70 in some situations can provide a greater and more secureattachment area against which the valve 1 can abut. Similar to the ringanchor 60 in FIG. 4A, at least a portion of the native mitral valveleaflets 88 and/or the chordae 90 are pinched between the valve 1 andthe helical anchor 70. Methods and devices for implanting helicalanchors and prosthetic valves are described in U.S. application Ser. No.15/682,287, filed on Aug. 21, 2017, and U.S. application Ser. No.15/684,836, filed on Aug. 23, 2017, which are incorporated herein byreference.

FIG. 4C illustrates another representative embodiment of a helicalanchor 300 that can be used in combination with any of the prostheticvalves described herein. The anchor 300 can be configured as a coilhaving a central region 302, a lower region 304, and an upper region306. The lower region 304 includes one or more turns in a helicalarrangement that can be configured to encircle or capture the chordaetendineae and/or the leaflets of the mitral valve. The central region302 includes a plurality of turns configured to retain the prostheticvalve in the native annulus. The upper region 306 includes one or moreturns, and can be configured to keep the anchor from being dislodgedfrom the valve annulus prior to implantation of the prosthetic valve. Insome embodiments, the upper region 306 can be positioned over the floorof the left atrium, and can be configured to keep the turns of thecentral region 302 positioned high within the mitral apparatus.

The anchor 300 also includes an extension portion 308 positioned betweenthe central region 302 and the upper region 306. In other embodiments,the extension portion 308 can instead be positioned, for example, whollyin the central region 302 (e.g., at an upper portion of the centralregion) or wholly in the upper region 306. The extension portion 308includes a part of the coil that extends substantially parallel to acentral axis of the anchor. In other embodiments, the extension portion308 can be angled relative to the central axis of the anchor. Theextension portion 308 can serve to space the central region 302 and theupper region 306 apart from one another in a direction along the centralaxis so that a gap is formed between the atrial side and the ventricularside of the anchor.

The extension portion 308 of the anchor is intended to be positionedthrough or near the native valve annulus, in order to reduce the amountof the anchor that passes through, pushes, or rests against the nativeannulus and/or the native leaflets when the anchor is implanted. Thiscan reduce the force applied by the anchor on the native mitral valveand reduce abrasion of the native leaflets. In one arrangement, theextension portion 308 is positioned at and passes through one of thecommissures of the native mitral valve. In this manner, the extensionportion 308 can space the upper region 306 apart from the nativeleaflets of the mitral valve to prevent the upper region 306 frominteracting with the native leaflets from the atrial side. The extensionportion 308 also elevates the upper region 306 such that the upperregion contacts the atrial wall above the native valve, which can reducethe stress on and around the native valve, as well as provide for betterretention of the anchor.

In the illustrated embodiment, the anchor 300 can further include one ormore openings configured as through holes 310 at or near one or both ofthe proximal and distal ends of the anchor. The through holes 310 canserve, for example, as suturing holes for attaching a cover layer overthe coil of the anchor, or as an attachment site for delivery tools suchas a pull wire for a pusher or other advancement device. In someembodiments, a width or thickness of the coil of the anchor 300 can alsobe varied along the length of the anchor. For example, a central portionof the anchor can be made thinner than end portions of the anchor. Thiscan allow the central portion to exhibit greater flexibility, while theend portions can be stronger or more robust. In certain examples, makingthe end portions of the coil relatively thicker can also provide moresurface area for suturing or otherwise attaching a cover layer to thecoil of the anchor.

In certain embodiments, the helical anchor 300 can be configured forinsertion through the native valve annulus in a counter-clockwisedirection. For example, the anchor can be advanced through commissureA3P3, commissure A1P1, or through another part of the native mitralvalve. The counter-clockwise direction of the coil of the anchor 300 canalso allow for bending of the distal end of the delivery catheter in asimilar counter-clockwise direction, which can be easier to achieve thanto bend the delivery catheter in the clockwise direction. However, itshould be understood that the anchor can be configured for eitherclockwise or counter-clockwise insertion through the valve, as desired.

Returning to the prosthetic valve of FIG. 3, the prosthetic valve 1generally includes a metal frame 10 that forms a number of edges. Inaddition, many frames 10 are constructed with edged crowns or apices 14and protruding commissure attachment posts 11, as well as threads 40that can be exposed along an outer surface of the frame 10. Thesefeatures can cause damage to the native mitral tissue, such as tissuelodged between the prosthetic valve 1 and the anchor 60, 70, forexample, by movement or friction between the native tissue and thevarious abrasive surfaces of the prosthetic valve 1. In addition, othernative tissue in close proximity to the prosthetic valve 1, such as thechordae tendinae, can also potentially be damaged.

FIGS. 5-7 illustrate a representative embodiment of a prosthetic heartvalve 100 similar to the Edwards Lifesciences SAPIEN™ 3 valve, which isdescribed in detail in U.S. Pat. No. 9,393,110, which is incorporatedherein by reference. The prosthetic valve 100 includes a frame 102formed by a plurality of angled strut members 104, and having an inflowend 106 and an outflow end 108. The prosthetic valve 100 also includes aleaflet structure comprising three leaflets 110 situated at leastpartially within the frame 102 and configured to collapse in a tricuspidarrangement similar to the aortic valve, although the prosthetic valvecan also include two leaflets configured to collapse in a bicuspidarrangement in the manner of the mitral valve, or more than threeleaflets, as desired. The strut members 104 can form a plurality ofapices 124 arranged around the inflow and outflow ends of the frame.

The prosthetic heart valve can include an outer covering 112 configuredto cushion (protect) native tissue in contact with the prosthetic valveafter implantation, and to reduce damage to the tissue due to movementor friction between the tissue and surfaces of the valve. The covering112 can also reduce paravalvular leakage. In the embodiment of FIG. 5,the covering 112 includes a first layer configured as a backing layer114 (see, e.g., FIG. 8), and a second layer configured as a cushioninglayer 116. The cushioning layer 116 can be disposed on the backing layer114, and can comprise a soft, plush surface 118 oriented radiallyoutward so as to protect tissue or objects in contact with thecushioning layer. In the illustrated configuration, the covering 112also includes an atraumatic inflow protective portion 120 extendingcircumferentially around the inflow end 106 of the frame, and anatraumatic outflow protective portion 122 extending circumferentiallyaround the outflow end 108 of the frame. The portion of the cushioninglayer 116 between the inflow and outflow protective portions 120, 122can define a main cushioning portion 136.

FIG. 8 is a cross-sectional view schematically illustrating theprosthetic valve 100 with the leaflet structure removed for purposes ofillustration. The covering 112 extends around the exterior of the frame102, such that an interior surface of the backing layer 114 is adjacentor against the exterior surfaces of the strut members 104. Asillustrated in FIG. 8, the cushioning layer 116 can have a length thatis greater than the length of the frame as measured along a longitudinalaxis 126 of the frame. Thus, the covering 112 can be situated such thatthe cushioning layer 116 extends distally (e.g., in the upstreamdirection) beyond the apices 124 of the strut members at the inflow end106 of the frame, with the portion of the cushioning layer extendingbeyond the apices being referred to herein as distal end portion 128. Atthe opposite end of the valve, the cushioning layer 116 can extendproximally (e.g., in the downstream direction) beyond the apices 124 ofthe strut members, with the portion located beyond the apices beingreferred to as proximal end portion 130. The distances by which theproximal and distal end portions 128, 130 of the cushioning layer 116extend beyond the apices at the respective end of the valve can be thesame or different depending upon, for example, the dimensions of thevalve, the particular application, etc.

The backing layer 114 can have sufficient length in the axial directionsuch that a proximal end portion or flap 132 of the backing layer 114can be folded over the proximal end portion 130 of the cushioning layer116 in the manner of a cuff to form the outflow protective portion 122.Meanwhile, a distal end portion or flap 134 of the backing layer 114 canbe folded over the distal end portion 128 of the cushioning layer 116 toform the inflow protective portion 120. The proximal and distal flaps132, 134 of the backing layer 116 can be secured to the underlyingsection of the backing layer by, for example, sutures 136. In thismanner, the inflow and outflow protective portions 120, 122 areconstructed such that the proximal and distal end portions 130, 128 ofthe cushioning layer 116 are at least partially enclosed by the flaps132, 134 of the backing layer 116. This construction provides sufficientstrength and resistance to bending to the inflow and outflow protectiveportions 120, 122 so that they extend along the longitudinal axis 126 ofthe valve without bending or otherwise protruding into the innerdiameter of the valve (e.g., by bending under their own weight, by bloodflow, or by blood pressure). In this manner, the inflow and outflowprotective portions 120, 122 minimally impact flow through theprosthetic valve and avoid interfering with the prosthetic valveleaflets, reducing flow disturbances and the risk of thrombus.

In the illustrated configuration, the inflow protective portion 120 canextend beyond the apices 124 of the strut members at the inflow end ofthe frame by a distance d₁, and the outflow protective portion 122 canextend beyond the apices 124 of the strut members at the outflow end ofthe frame by a distance d₂. The distances d₁ and d₂ can be the same ordifferent, depending upon the type of prosthetic valve, the treatmentlocation, etc. For example, for a 29 mm prosthetic valve, the distancesd₁ and d₂ can be from about 0.5 mm to about 3 mm. In a representativeembodiment, the distances d₁ and d₂ can be from about 1 mm to about 2mm. Because the inflow and outflow protective portions 120, 122 extendbeyond the apices 124 of the respective ends of the frame, the inflowand outflow protective portions can shield adjacent tissue and/oranother implant adjacent the prosthetic valve from contacting the apices124 of the frame.

For example, FIG. 10 illustrates the prosthetic valve 100 implantedwithin a helical anchor 70 in the native mitral valve 86, similar toFIGS. 4A and 4B above. In the illustrated example, the inflow endportion of the prosthetic valve is positioned above the superior surfaceof the native mitral valve annulus and spaced from surrounding tissue.However, in other implementations, depending on the axial positioning ofthe prosthetic valve, the inflow protective portion 120 can contact thenative leaflets 88 and prevent them from directly contacting the apices124 at the inflow end of the frame. Depending on the diameter of theprosthetic valve at the inflow end, the inflow protective portion 120can serve to prevent the atrium wall from directly contacting the apices124 at the inflow end of the frame.

As shown in FIG. 10, the anchor 70 can also rest against the compliantinflow protective portion 120. Meanwhile, the portions of the nativeleaflets 88 captured between the anchor 70 and the prosthetic valve 100can be cushioned by the plush surface 118 of the main cushioning portion136. In certain embodiments, the soft, compliant nature and texture ofthe cushioning layer 116 can increase friction between the nativeleaflets and the prosthetic valve. This can reduce relative movement ofthe native leaflets and the prosthetic valve as the left ventricleexpands and contracts, reducing the likelihood of damage to the nativeleaflets and the surrounding tissue. The cushioning layer 116 can alsoprovide increased retention forces between the anchor 70 and theprosthetic valve 100. The plush, compressible nature of the cushioninglayer 116 can also reduce penetration of the covering 112 through theopenings in the frame 102 caused by application of pressure to thecovering, thereby reducing interference with the hemodynamics of thevalve. Additionally, the outflow cushioning portion 122 can protect thechordae tendineae 90 from contacting the strut members of the frame, andin particular the apices 124 at the outflow end of the frame, therebyreducing the risk of injury or rupture of the chordae.

The backing layer 114 can comprise, for example, any of various wovenfabrics, such as gauze, polyethylene terephthalate (PET) fabric (e.g.,Dacron), polyester fabric, polyamide fabric, or any of various non-wovenfabrics, such as felt. In certain embodiments, the backing layer 114 canalso comprise a film including any of a variety of crystalline orsemi-crystalline polymeric materials, such as polytetrafluorethylene(PTFE), PET, polypropylene, polyamide, polyetheretherketone (PEEK), etc.In this manner, the backing layer 114 can be relatively thin and yetstrong enough to allow the covering 112 to be sutured to the frame, andto allow the prosthetic valve to be crimped, without tearing.

As stated above, the cushioning layer 116 can comprise at least onesoft, plush surface 118. In certain examples, the cushioning layer 116can be made from any of a variety of woven or knitted fabrics whereinthe surface 116 is the surface of a plush nap or pile of the fabric.Exemplary fabrics having a pile include velour, velvet, velveteen,corduroy, terrycloth, fleece, etc. FIG. 9 illustrates a representativeembodiment of the cushioning layer 116 in greater detail. In theembodiment of FIG. 9, the cushioning layer 116 can have a base layer 162(a first layer) from which the pile 158 (a second layer) extends. Thebase layer 162 can comprise warp and weft yarns woven or knitted into amesh-like structure. For example, in a representative configuration, theyarns of the base layer 162 can be flat yarns with a denier range offrom about 7 dtex to about 100 dtex, and can be knitted with a densityof from about 20 to about 100 wales per inch and from about 30 to about110 courses per inch. The yarns can be made from, for example,biocompatible thermoplastic polymers such as PET, Nylon, ePTFE, etc.,other suitable natural or synthetic fibers, or soft monolithicmaterials.

The pile 158 can comprise pile yarns 164 woven or knitted into loops. Incertain configurations, the pile yarns 164 can be the warp yarns or theweft yarns of the base layer 162 woven or knitted to form the loops. Thepile yarns 164 can also be separate yarns incorporated into the baselayer, depending upon the particular characteristics desired. In certainembodiments, the loops can be cut such that the pile 158 is a cut pilein the manner of, for example, a velour fabric. FIGS. 5-8 illustrate arepresentative embodiment of the cushioning layer 116 configured as avelour fabric. In other embodiments, the loops can be left intact toform a looped pile in the manner of, for example, terrycloth. FIG. 9illustrates a representative embodiment of the cushioning layer 116 inwhich the pile yarns 164 are knitted to form loops 166. FIG. 11illustrates an embodiment of the covering 112 incorporating thecushioning layer 116 of FIG. 9.

In some configurations, the pile yarns 164 can be textured yarns havingan increased surface area due to, for example, a wavy or undulatingstructure. In configurations such as the looped pile embodiment of FIG.11, the loop structure and the increased surface area provided by thetextured yarn of the loops 166 can allow the loops to act as a scaffoldfor tissue growth into and around the loops of the pile. Promotingtissue growth into the pile 158 can increase retention of the valve atthe implant site and contribute to long-term stability of the valve.

The cushioning layer embodiments described herein can also contribute toimproved compressibility and shape memory properties of the covering 112over known valve coverings and skirts. For example, the pile 158 can becompliant such that it compresses under load (e.g., when in contact withtissue, implants, or the like), and returns to its original size andshape when the load is relieved. This can help to improve sealingbetween the cushioning layer 116 and, for example, support structures orother devices such as the helical anchor 70 in which the prostheticvalve is deployed, or between the cushioning layer and the walls of thenative annulus. The compressibility provided by the pile 158 of thecushioning layer 116 is also beneficial in reducing the crimp profile ofthe prosthetic valve. Additionally, the covering 112 can prevent theleaflets 110 or portions thereof from extending through spaces betweenthe strut members 104 as the prosthetic valve is crimped, therebyreducing damage to the prosthetic leaflets due to pinching of theleaflets between struts.

In alternative embodiments, the cushioning layer 116 be made ofnon-woven fabric such as felt, or fibers such as non-woven cottonfibers. The cushioning layer 116 can also be made of porous or spongeymaterials such as, for example, any of a variety of compliant polymericfoam materials, or woven or knitted fabrics, such as woven or knittedPET. In further alternative embodiments, the proximal and distal endportions of the cushioning layer 116 of the embodiment of FIG. 11 can befree of loops 166, and the inflow and outflow protective portions 120,122 can be formed by folding the base layer 162 back on itself to formcuffs at the inflow and outflow ends of the valve.

In a representative example illustrated in FIG. 12, the covering 112 ofFIGS. 5-8 can be made by cutting a fabric material (e.g., a PET fabric)with a stencil 138 to form the backing layer 114. In the illustratedembodiment, the stencil 138 is shaped like a parallelogram, althoughother configurations are possible. The angles of the corners of thestencil 138 can be shaped such that the fabric material is cut at abouta 45 degree angle relative to the direction of the fibers of the fabric.This can improve the crimpability of the resulting backing layer 114 by,for example, allowing the backing layer to stretch along a directiondiagonal to the warp and weft yarns. FIG. 18 illustrates a plan view ofa representative example of the backing layer 114 after being cut usingthe parallelogram stencil 138.

The cushioning layer 116 can be attached (e.g., by sutures, adhesive,etc.) to the backing layer 114. In FIG. 12, the location of the proximaland distal ends of the frame 102 when the covering is attached to theframe are represented as dashed lines 140, 141 on the backing layer 114.Meanwhile, dashed lines 142, 144 represent the location of the proximaland distal edges of the cushioning layer 116 once the cushioning layeris secured to the backing layer. For example, the cushioning layer 116can be sutured to the backing layer 114 along the proximal and distaledges at or near lines 142, 144. As shown in FIG. 12, line 142representing the proximal edge of the cushioning layer 116 can be offsetfrom the proximal edge 146 of the backing layer 114 by a distance d₃ tocreate the proximal flap 132. Meanwhile, line 144 representing thedistal edge of the cushioning layer 116 can be offset from the distaledge 148 of the backing layer 114 by a distance d₄ to create the distalflap 134. The distances d₃ and d₄ can be the same or different, asdesired. For example, depending upon the size of the valve and the sizeof the inflow and outflow cushioning portions, the distances d₃ and d₄can be, for example, about 3-5 mm. In some embodiments, the distances d₃and d₄ can be about 3.5 mm.

Once the cushioning layer 116 is secured to the backing layer 114, theresulting swatch can be folded and sutured into a cylindrical shape. Theflaps 132, 134 of the backing layer 114 can be folded over the edges ofthe cushioning layer 116 and sutured to form the inflow and outflowprotective portions 120, 122. The resulting covering 112 can then besecured to the frame 102 by, for example, suturing it the strut members104.

FIGS. 13 and 14 illustrate another embodiment of the covering 112 inwhich the inflow and outflow protective portions 120, 122 are formedwith separate pieces of material that wrap around the ends of thecushioning layer 116 at the inflow and outflow ends of the valve. Forexample, the proximal end portion 130 of the cushioning layer 116 can becovered by a member configured as a strip 150 of material that wrapsaround the cushioning layer from the interior surface 170 (e.g., thesurface adjacent the frame) of the cushioning layer 116, over thecircumferential edge of the proximal end portion 130, and onto theexterior surface 118 of the cushioning layer to form the outflowprotective portion 122. Likewise, a material strip member 152 can extendfrom the interior surface 170 of the cushioning layer, over thecircumferential edge of the distal end portion 128, and onto theexterior surface of the cushioning layer to form the inflow protectiveportion 120. The strip members 150, 152 can be sutured to the cushioninglayer 116 along the proximal and distal edge portions 130, 128 of thecushioning layer at suture lines 154, 156, respectively.

In certain configurations, the strip members 150, 152 can be made fromany of various natural materials and/or tissues, such as pericardialtissue (e.g., bovine pericardial tissue). The strip members 150, 152 canalso be made of any of various synthetic materials, such as PET and/orexpanded polytetrafluoroethylene (ePTFE). In some configurations, makingthe strip members 150, 152 from natural tissues such as pericardialtissue can provide desirable properties such as strength, durability,fatigue resistance, and compliance, and cushioning and reduced frictionwith materials or tissues surrounding the implant.

FIG. 15 illustrates a prosthetic valve 200 including another embodimentof an outer covering 202 comprising a cushioning layer 204 made of aspacer fabric. In the illustrated embodiment, the outer covering 202 isshown without inflow and outflow protective portions, and with thecushioning layer 204 extending along the full length of the frame fromthe inflow end to the outflow end of the valve. However, the outercovering 202 may also include inflow and/or outflow protective portions,as described elsewhere herein.

Referring to FIGS. 16 and 17, the spacer fabric cushioning layer cancomprise a first layer 206, a second layer 208, and a spacer layer 210extending between the first and second layers to create athree-dimensional fabric. The first and second layers 206, 208 can bewoven fabric or mesh layers. In certain configurations, one or more ofthe first and second layers 206, 208 can be woven such that they definea plurality of openings 212. In some examples, openings such as theopenings 212 can promote tissue growth into the covering 202. In otherembodiments, the layers 206, 208 need not define openings, but can beporous, as desired.

The spacer layer 210 can comprise a plurality of pile yarns 214. Thepile yarns 214 can be, for example, monofilament yarns arranged to forma scaffold-like structure between the first and second layers 206, 208.For example, FIGS. 16 and 17 illustrate an embodiment in which the pileyarns 214 extend between the first and second layers 206, 208 in asinusoidal or looping pattern.

In certain examples, the pile yarns 214 can have a rigidity that isgreater than the rigidity of the fabric of the first and second layers206, 208 such that the pile yarns 214 can extend between the first andsecond layers 206, 208 without collapsing under the weight of the secondlayer 208. The pile yarns 214 can also be sufficiently resilient suchthat the pile yarns can bend or give when subjected to a load, allowingthe fabric to compress, and return to their non-deflected state when theload is removed.

The spacer fabric can be warp-knitted, or weft-knitted, as desired. Someconfigurations of the spacer cloth can be made on a double-bar knittingmachine. In a representative example, the yarns of the first and secondlayers 206, 208 can have a denier range of from about 10 dtex to about70 dtex, and the yarns of the monofilament pile yarns 214 can have adenier range of from about 2 mil to about 10 mil. The pile yarns 214 canhave a knitting density of from about 20 to about 100 wales per inch,and from about 30 to about 110 courses per inch. Additionally, in someconfigurations (e.g., warp-knitted spacer fabrics) materials withdifferent flexibility properties may be incorporated into the spacercloth to improve the overall flexibility of the spacer cloth.

FIGS. 19-21 illustrate another embodiment of a prosthetic heart valve400 including an outer covering with inflow and outflow protectiveportions that encapsulate the apices of the strut members. For example,the prosthetic valve can include a frame 402 formed by a plurality ofstrut members 404 defining apices 420 (FIGS. 22 and 24), and can have aninflow end 406 and an outflow end 408. A plurality of leaflets 410 canbe situated at least partially within the frame 402.

The prosthetic valve can include an outer covering 412 situated aboutthe frame 402. The outer covering 412 can include a main cushioninglayer 414 including a plush exterior surface 432 (e.g., a firstsurface), similar to the cushioning layer 116 of FIG. 13 above. Thecovering 412 can also include an inflow protective portion 416 extendingcircumferentially around the inflow end 406 of the valve, and an outflowprotective portion 418 extending circumferentially around the outflowend 408 of the valve. The inflow and outflow protective portions 416,418 can be formed with separate pieces of material that are foldedaround the circumferential ends of the cushioning layer 414 at theinflow and outflow ends of the valve such that the protective portionsencapsulate the apices 420 of the strut members.

For example, with reference to FIG. 22, the inflow protective portion416 can comprise a member configured as a strip 424 of materialincluding a first circumferential edge portion 426 and a secondcircumferential edge portion 428. The strip member 424 of material canbe folded such that the first circumferential edge portion 426 isadjacent (e.g., contacting) an inner skirt 430 disposed within the frame402. The first circumferential edge portion 426 thereby forms a first orinner layer of the inflow protective portion 416. The strip member 424can extend over the apices 420 of the strut members, and over an inflowend portion 422 of the cushioning layer 414 such that the secondcircumferential edge portion 428 is disposed on the exterior surface 432of the cushioning layer 414. In this manner, the inflow end portion 422of the cushioning layer 414 can form a second layer of the inflowprotective portion 414, and the second circumferential edge portion 428can form a third or outer layer of the inflow protective portion. Thefirst and second circumferential edge portions 426, 428 of the stripmember 424 can be secured to the strut members 404 (e.g., the rung ofstruts nearest the inflow end 406) with sutures 434, 435. Thus, thestrip member 424 can encapsulate the apices 420, along with the inflowend portion 422 of the cushioning layer 414, between the first andsecond circumferential edge portions 426, 428.

In the illustrated configuration, the inflow protective portion 416 canextend beyond the apices 420 of the frame, similar to the embodimentsabove. In particular, the inflow end portion 422 of the cushioning layer414 can extend beyond the apices 420 of the frame and into the inflowprotective portion 416 within the folded strip 424. In this manner, theinflow end portion 422 of the cushioning layer 414, together with thestrip member 424, can impart a resilient, cushioning quality to theinflow protective portion 416. This can also allow the inflow protectiveportion 416 to resiliently deform to accommodate and protect, forexample, native tissue, other implants, etc., that come in contact withthe inflow protective portion.

In the illustrated embodiment, the inflow end portion 422 can extendbeyond the apices 420 by a distance d₁. The distance d₁ can beconfigured such the inflow end portion 422 can extend over or cover theapices 420 when the inflow protective portion 416 comes in contact with,for example, native tissue at the treatment site. The strip member 424can also form a dome over the edge of the of the inflow end portion 422such that the edge of the inflow end portion 422 is spaced apart fromthe domed portion of the strip member 424. In other embodiments, thestrip member 424 can be folded such that it contacts the edge of theinflow edge portion 422, similar to the embodiment of FIG. 13.

The outflow protective portion 418 can include a member configured as astrip 436 of material folded such that a first circumferential edgeportion 438 is adjacent (e.g., contacting) inner surfaces 440 of thestrut members, and a second circumferential edge portion 442 is disposedon the exterior surface 432 of the cushioning layer 414, similar to theinflow protective portion 416. An outflow end portion 444 of thecushioning layer 414 can extend beyond the apices 420 by a distance d₂,and can be encapsulated by the strip member 436 together with the apices420 between the first and second circumferential edge portions 438, 442.The distance d₂ can be the same as distance d₁ or different, as desired.The strip member 436 can be secured to the strut members 404 withsutures 446, 447. The strip member 436 can also form a domed shapesimilar to the strip member 424.

In certain configurations, the cushioning layer 414 can be a fabricincluding a plush pile, such as a velour fabric, or any other type ofplush knitted, woven, or non-woven material, as described above. In someembodiments, the cushioning layer 414 may also comprise a relatively lowthickness woven fabric without a plush pile. In certain configurations,the strip members 424, 436 can be made of resilient natural tissuematerials such as pericardium. Alternatively, the strip members can alsobe made from fabric or polymeric materials such as PTFE or ePTFE.

FIGS. 23-26 illustrate a representative method of making the outercovering 412 and attaching the covering to the prosthetic valve 400 toform the inflow and outflow protective portions 416, 418. FIG. 23illustrates the outer covering 412 in an unfolded configuration prior tosecuring the covering to the frame 402. As illustrated in FIG. 23, thesecond circumferential edge portion 428 of the strip member 424 can besutured to the plush surface 432 (e.g., the first surface) of thecushioning layer 414 at the inflow end portion 422 of the cushioninglayer. The second circumferential edge portion 442 of the strip member436 can be sutured to the plush surface 432 of the cushioning layer 414at the outflow end portion 444 of the cushioning layer.

In the illustrated configuration, the cushioning layer 414 and the stripmembers 424, 436 can have a length dimension L corresponding to acircumference of the frame 402. In a representative example, the lengthdimension L can be about 93 mm. The strip members 424, 436 can also haverespective width dimensions W₁, W₂. Referring to width dimension W₁ forpurposes of illustration, the width dimension W₁ can be configured suchthat the strip member 424 extends from the interior of the valve to theexterior of the valve without contacting the apices 420 of the strutmembers, as shown in FIG. 22. For example, the width dimension W₁ can beconfigured such that the strip member 424 extends from adjacent the rungof strut members 404 at the inflow end 406 of the frame to the exteriorof the valve adjacent the same rung of strut members and forms a domedshape over the apices 420. In certain configurations, the widthdimension W₁ can be about 6 mm. The width dimension W₂ can be the sameas W₁ or different, as desired.

Referring to FIG. 24, the outer covering 412 can be folded and suturedinto a cylindrical shape. The outer covering 412 can then be situatedaround the frame 402 such that a second or interior surface 454 of thecushioning layer 414 is oriented toward the frame. In certainconfigurations, the frame 402 can already include the inner skirt 430and the leaflet structure 410, as shown in FIG. 24.

Referring to FIGS. 25 and 26, the outer covering 412 can then be suturedto the frame. For example, as illustrated in FIG. 25, the strip member424 can be aligned with an adjacent rung of strut members 404 (e.g., therung of strut members nearest the inflow end of the frame). Thecushioning layer 414 and/or the strip member 424 can then be sutured tothe strut members 404 at suture line 434. The strip member 424 can thenbe folded over the apices 420 at the inflow end of the frame, and thefirst and second circumferential edge portions 426, 428 can be suturedto each other at suture line 435 to form the inflow protective portion416. In other embodiments, the strip member 424 can be folded andsutured to form the inflow protective portion 416 before the outercovering 412 is sutured to the frame.

The outflow protective portion 418 can be formed in a similar manner.For example, the strip member 426 can be aligned with the rung of strutmembers 404 adjacent the outflow end 408 of the frame, and the stripmember 426 and/or the cushioning layer 414 can be sutured to the strutmembers. The strip member 436 can then be folded over the apices 420 andthe cushioning layer 414 at the outflow end of the frame, and the firstand second circumferential edge portions 438, 442 can be suturedtogether, and to the rung of strut members 404 adjacent the outflow endof the frame, to form the outflow protective portion 418. The covering412 can also be sutured to the frame at one or more additionallocations, such as at suture lines 448 and 450, as shown in FIG. 22.

FIGS. 27 and 28 illustrates another embodiment of a prosthetic heartvalve 500 including a frame 502 formed by a plurality of strut members504 defining apices 506 (FIG. 28), similar to the frame 102 describedabove and in U.S. Pat. No. 9,393,110. The prosthetic valve 500 can havean inflow end 508 and an outflow end 510, and can include a leafletstructure (not shown) situated at least partially within the frame.

The prosthetic valve can include an outer covering 514 situated aboutthe frame 502. The outer covering 514 can include a main cushioninglayer 516 (also referred to as a main layer) having a cylindrical shape,and made from a woven, knitted, or braided fabric (e.g., a PET fabric,an ultra-high molecular weight polyethylene (UHMWPE) fabric, a PTFEfabric, etc.). In some embodiments, the fabric of the main cushioninglayer 516 can include a plush pile. In some embodiments, the fabric ofthe main cushioning layer 516 can comprise texturized yarns in which theconstituent fibers of the yarns have been bulked by, for example, beingtwisted, heat set, and untwisted such that the fibers retain theirdeformed, twisted shape and create a voluminous fabric. The volumecontributed by the texturized yarns can improve the cushioningproperties of the covering, as well as increase friction between thefabric and the surrounding anatomy and/or an anchoring device into whichthe valve is deployed.

The outer covering 514 can include an inflow protective portion 518extending circumferentially around the inflow end 508 of the frame, andan outflow protective portion 520 extending circumferentially around theoutflow end 510 of the frame. In certain embodiments, the inflow andoutflow protective portions 518 and 520 can be formed on the fabric ofthe main cushioning layer 516 such that the outer covering 514 is aone-piece, unitary construction, as described further below.

Referring to FIG. 28, the main cushioning layer 516 can include a firstcircumferential edge portion 522 (also referred to as an inflow edgeportion) located adjacent the inflow end 508 of the valve, which canform a part of the inflow protective portion 518. The cushioning layer516 can further include a second circumferential edge portion 524 (alsoreferred to as an outflow edge portion) located adjacent the outflow end510 of the valve, and which can form a part of the outflow protectiveportion 520. Referring still to FIG. 28, the first circumferential edgeportion 522 can comprise an edge 526, and the second circumferentialedge portion 524 can comprise an edge 528. The first circumferentialedge portion 522 can be folded or wrapped over the apices 506 of thestrut members 504 such that the edge 526 is disposed on the inside ofthe frame 502. The second circumferential edge portion 524 can be foldedaround the apices 506 at the outflow end 510 of the frame in a similarfashion such that the edge 528 is also disposed on the inside of theframe opposite the edge 522.

In the illustrated configuration, the inflow protective portion 518 caninclude a second or outer layer configured as a lubricious layer 530 ofmaterial disposed on an outer surface 532 of the main cushioning layer516. The outflow protective portion 520 can also include a second orouter lubricious layer 534 of material disposed on the outer surface 532of the main cushioning layer 516. In some embodiments, the layers 530and 534 can be smooth, low-thickness coatings comprising a low-frictionor lubricious material. For example, in certain configurations one orboth of the layers 530, 534 can comprise PTFE or ePTFE.

In the illustrated configuration, the lubricious layer 530 can have afirst circumferential edge 536 (FIG. 27) and a second circumferentialedge 538 (FIG. 28). The lubricious layer 530 can extend from the outersurface 532 of the main cushioning layer 516 and over the apices 506such that the first circumferential edge 536 is disposed on the outsideof the frame and the second circumferential edge 538 is disposed on theinside of the frame. The lubricious layer 534 can be configuredsimilarly, such that a first circumferential edge 540 (FIG. 27) isdisposed outside the frame, the layer 534 extends over the apices 506 ofthe outflow end 510 of the frame, and a second circumferential edge 542(FIG. 28) is disposed inside the frame. Once implanted in a native heartvalve, the protection portions 518 and 520 can prevent direct contactbetween the apices 506 and the surrounding anatomy. The lubriciousmaterial of the layers 530 and 534 can also reduce friction with tissueof the native valve (e.g., chordae) in contact with the inflow andoutflow ends of the prosthetic valve, thereby preventing damage to thetissue. In other embodiments, the entire outer surface 532 of the maincushioning layer 516, or a portion thereof, can be covered with alubricious coating such as ePTFE in addition to the inflow and outflowprotective portions 518 and 520 such that the lubricious coating extendsaxially from the inflow end to the outflow end of the covering. In yetother embodiments, the cushioning layer 516 can be formed from woven,knitted, braided, or electrospun fibers of lubricious material, such asPTFE, ePTFE, etc., and can form the inflow and outflow protectiveportions.

FIGS. 29-31B illustrate a representative method of making the covering514. FIG. 29 illustrates the main cushioning layer 516 formed into acylindrical, tubular body. Referring to FIG. 30, the firstcircumferential edge portion 522 of the cushioning layer 516 can then befolded over (e.g, inward toward the interior surface of the tubularbody) in the direction of arrows 544 such that the lower edge 526 isinside the tubular body and disposed against the interior surface of thetubular body. The edge portion 524 can be folded in a similar manner asindicated by arrows 546 such that the top edge 528 is inside the tubularbody and disposed against the interior surface.

Referring to FIGS. 31A and 31B, the lubricious layers 530, 534 can thenbe applied to the main layer 516 to form the inflow and outflowprotection portions 518 and 520. In certain embodiments, the lubriciouslayers 530, 534 can be formed by electrospinning a low-friction material(e.g., PTFE, ePTFE, etc.) onto the first and second circumferential edgeportions 522 and 524. In certain embodiments, forming the layers 530,and 534 by electrospinning can provide a smooth, uniform surface, andkeep the thickness of the layers within strictly prescribedspecifications.

For example, the layers 530 and 534 can be made relatively thin, whichcan reduce the overall crimp profile of the valve. In certainembodiments, a thickness of the layers 530 and 534 can be from about 10μm to about 500 μm, about 100 μm to about 500 μm, about 200 μm to about300 μm, about 200 μm, or about 300 μm. In other embodiments, the layer530 and/or 534 can be made by dip-coating, spray-coating, or any othersuitable method for applying a thin layer of lubricious material to themain cushioning layer 516. The finished outer covering 514 can then besituated about and secured to the frame 502 using, for example, sutures,ultrasonic welding, or any other suitable attachment method. In otherembodiments, the main cushioning layer 516 can be situated about theframe 502 before the edges are folded, and/or before the lubriciouslayers 530 and 534 are applied. In yet other embodiments, one or both ofthe lubricious layers 530 and/or 534 can be omitted from the first andsecond circumferential edge portions 522 and 524. In yet otherembodiments, one or both of the first and second circumferential edgeportions 522, 524 need not be folded inside the frame, but may extend tothe respective inflow or outflow end of the frame, or beyond the ends ofthe frame on the exterior of the frame, as desired.

In addition to covering the frame 502 and the apices 506, the outercovering 514 can provide a number of other significant advantages. Forexample, the covering 514 can be relatively thin, allowing theprosthetic valve to achieve a low crimp profile (e.g., 23 Fr or below).The one-piece, unitary construction of the outer covering 514 and theprotective portions 518 and 520 can also significantly reduce the timerequired to produce the covering and secure it to the frame, and canincrease production yield.

In some embodiments, one or both of the inflow and outflow protectionportions can be configured as separate coverings that are spaced apartfrom the main outer covering, and may or may not be coupled to the mainouter covering. For example, FIGS. 32-36 illustrate another embodimentof a prosthetic heart valve 600 including a frame 602 formed by aplurality of strut members 604 defining apices 606, similar to the frame102 described above and in U.S. Pat. No. 9,393,110. The prosthetic valve600 can have an inflow end 608 and an outflow end 610, and can include aplurality of leaflets 612 situated at least partially within the frame.

FIG. 34 illustrates a portion of the frame 602 in a laid-flatconfiguration for purposes of illustration. The strut members 604 can bearranged end-to-end to form a plurality of rows or rungs of strutmembers that extend circumferentially around the frame 602. For example,with reference to FIG. 34, the frame 602 can comprise a first or lowerrow I of angled strut members forming the inflow end 608 of the frame; asecond row II of strut members above the first row; a third row III ofstrut members above the second row; a fourth row IV of strut membersabove the third row, and a fifth row V of strut members above the fourthrow and forming the outflow end 610 of the frame. At the outflow end 610of the frame, the strut members 604 of the fifth row V can be arrangedat alternating angles in a zig-zag pattern. The strut members 604 of thefifth row V can be joined together at their distal ends (relative to thedirection of implantation in the mitral valve) to form the apices 606,and joined together at their proximal ends at junctions 630, which mayform part of the commissure windows 638. Additional structure andcharacteristics of the rows I-V of strut members 604 are described ingreater detail in U.S. Pat. No. 9,393,110, incorporated by referenceabove.

Returning to FIGS. 32 and 33, the prosthetic valve can include a firstcovering 614 (also referred to as a main covering) situated about theframe 602. The valve can also include an outflow protective portionconfigured as a second covering 616 disposed about the strut members 604and the apices 606 of the fifth row V of strut members at the outflowend 610 of the frame. The first covering 616 can comprise a woven orknitted fabric made from, for example, PET, UHMWPE, PTFE, etc. Referringto FIG. 33, the first covering 614 can include an inflow end portion 618located at the inflow end 608 of the valve, and an outflow end portion620 located at the outflow end 610 of the valve. In the illustratedembodiment, the outflow end portion 620 of the first covering 614 can beoffset toward the inflow end of the frame (e.g., in the upstreamdirection) from the fifth row V of strut members 604. Stateddifferently, the strut members 604 of the fifth row V can extend beyondan uppermost circumferential edge 622 of the first covering 614 (e.g.,distally beyond the edge 622 when the prosthetic valve is implanted inthe mitral valve). A lowermost circumferential edge 624 of the maincovering 614 can be disposed adjacent the first row I of strut members604 at the inflow end 608 of the valve. In some embodiments, the firstcovering 614 can extend over and cover the apices 606 at the inflow end608 of the frame.

FIG. 35 illustrates the frame 602 including the second covering 616 andan inner skirt 640, and without the first covering 614 for purposes ofillustration. In certain embodiments, the second covering 616 can beconfigured as a wrapping that extends around the circumference of theframe 602 and surrounds the fifth row V of strut members 604. Forexample, with reference to FIG. 36, the covering 616 can be configuredas one or more straps or strips 626 of material that are helicallywrapped around the struts 604 and the apices 606 of the fifth row V ofstrut members at the outflow end 610 of the frame in the direction suchas indicated by arrow 632. In certain configurations, second covering616 can be made of a lubricious or low-friction polymeric material, suchas PTFE, ePTFE, UHMWPE, polyurethane, etc. In this manner, the secondcovering 616 can reduce friction between the second covering and nativetissue that is in contact with the outflow end 610 of the valve. Thecovering 616 can also prevent injury to native tissue by preventing itfrom directly contacting the apices 606.

In some embodiments, the strip 626 can be relatively thick to improvethe cushioning characteristics of the second covering 616. For example,in some embodiments, the strip 626 can be a PTFE strip having athickness of from about 0.1 mm to about 0.5 mm, and a width of fromabout 3 mm to about 10 mm. In a representative embodiment, the strip 626can have a thickness of about 0.25 mm, and a width of about 6 mm. Thesecond covering 616 can also include one or multiple layers. Forexample, the second covering 616 can include a single layer (e.g., asingle strip 626) wrapped around a row of struts of the frame. Thesecond covering may also include two layers, three layers, or more ofstrips wrapped around a row of struts of the frame. In some embodiments,the second covering 616 can comprise multiple layers made of differentmaterials. In certain configurations, the second covering 616 can alsobe porous, and can have a pore size and pore density configured topromote tissue ingrowth into the material of the second covering.

In some embodiments, the first covering 614 and/or the second covering616 can be secured to the frame by, for example, suturing. In someembodiments, the first and second coverings 614, 616 can also be securedto each other. For example, with reference to FIGS. 32 and 33, the firstcovering 614 can include one or more sutures 628 extendingcircumferentially around the outflow end portion 620 of the firstcovering in, for example, a running stitch. At or near the junctions 630(FIG. 34) of the fifth row V of strut members 604, the suture 628 canextend out of the stitch line (e.g., from the radially outward surfaceof the covering 614), and loop over the second covering 616. The suture628 can then reenter the covering 614 (e.g., on the radially inwardsurface of the covering 614) and resume the running stitch. In theillustrated embodiment, the suture 628 can loop over the second covering616 at the junctions 630. The loops of suture 628 thereby rest in“valleys” between the apices 606, and can serve to hold the secondcovering 616 in place on the strut members 602. The suture 628 can alsohold the first covering 614 in place while the valve is being crimped.

Still referring to FIGS. 32 and 33, the circumferential edge 622 of thefirst covering 614 can be relatively straight, while the second covering616 can conform to the angled or zig-zag pattern of the fifth row V ofstrut members 604. In this manner, the first and second coverings 614and 616 can define a plurality of gaps or openings 634 through the frame602 between the first and second coverings. In the illustratedembodiment, the openings 634 have a triangular shape, with the base ofthe triangle being defined by the edge 622 of the first covering 614,and the sides being defined by the second covering 616. The openings 634can be configured such that after the valve 600 is implanted, blood canflow in and/or out of the frame 602 through the openings. In thismanner, the space between the interior of the frame 602 and theventricular surfaces 638 of the leaflets 612 can be flushed or washed byblood flowing into and out of the openings 634 during operation of theprosthetic valve. This can reduce the risk of thrombus formation andleft ventricular outflow tract obstruction.

FIG. 37 illustrates the frame 602 including the second covering 616 in aradially collapsed or crimped delivery configuration on a shaft 636 of adelivery apparatus. As shown in FIG. 37, the second covering 616 canconform to the closely-packed, serpentine shape of the strut members 604as they move to the radially collapsed configuration. In certainconfigurations, the second covering 616 can closely mimic the shape anddirection of the strut members 604 without bulging, pleating, creasing,or bunching to maintain a low crimp profile. In other embodiments, theinflow end of the frame can also include a separate covering similar tothe covering 616.

FIGS. 38A, 38B, 39A, and 39B illustrate the prosthetic valve 400 ofFIGS. 19-26 including an outer covering 700, according to anotherembodiment. The outer covering 700 can include a main cushioning layer702 having a plush exterior surface 704. The covering 700 can alsoinclude an inflow protection portion 706 extending circumferentiallyaround the inflow end 406 of the valve, and an outflow protectionportion 708 extending circumferentially around the outflow end 408 ofthe valve. As in the embodiment of FIGS. 19-26, the inflow and outflowprotection portions 706, 708 can be formed with separate pieces ofmaterial that are folded around the circumferential ends of the mainlayer 702 such that the cushioning portions encapsulate the apices 420of the strut members at the inflow and outflow ends of the valve. Forexample, the inflow and outflow protection portions 706, 708 can beconstructed from strips of material (e.g., polymeric materials such asPTFE, ePTFE, etc., or natural tissues such as pericardium, etc.) foldedsuch that one circumferential edge of the strips is disposed against theinterior of the frame 402 (or an inner skirt within the frame), and theother circumferential edge is disposed against the outer surface of themain layer 702. The outer covering 700 can be secured to the frame 402using, for example, sutures, ultrasonic welding, or any other suitableattachment method.

The main layer 702 of the outer covering 700 can comprise a woven orknitted fabric. The fabric of the main layer 702 can be resilientlystretchable between a first, natural, or relaxed configuration (FIGS.38A and 38B), and a second, elongated, or tensioned configuration (FIGS.39A and 39B). When disposed on the frame 402, the relaxed configurationcan correspond to the radially expanded, functional configuration of theprosthetic valve, and the elongated configuration can correspond to theradially collapsed delivery configuration of the valve. Thus, withreference to FIG. 38A, the outer covering 700 can have a first length L₁when the prosthetic valve is in the expanded configuration, and a secondlength L₂ (FIG. 39A) that is longer than L₁ when the valve is crimped tothe delivery configuration, as described in greater detail below.

The fabric can comprise a plurality of circumferentially extending warpyarns 712 and a plurality of axially extending weft yarns 714. In someembodiments, the warp yarns 712 can have a denier of from about 1 D toabout 300 D, about 10 D to about 200 D, or about 10 D to about 100 D. Insome embodiments, the warp yarns 712 can have a thickness t₁ (FIG. 40A)of from about 0.01 mm to about 0.5 mm, about 0.02 mm to about 0.3 mm, orabout 0.03 mm to about 0.1 mm. In some embodiments, the warp yarns 712can have a thickness t₁ of about 0.03 mm, about 0.04 mm, about 0.05 mm,about 0.06 mm, about 0.07 mm, about 0.08 mm, about 0.09 mm, or about 0.1mm. In a representative embodiment, the warp yarns 712 can have athickness of about 0.06 mm.

The weft yarns 714 can be texturized yarns comprising a plurality oftexturized filaments 716. For example, the filaments 716 of the weftyarns 714 can be bulked, wherein, for example, the filaments 716 aretwisted, heat set, and untwisted such that the filaments retain theirdeformed, twisted shape in the relaxed, non-stretched configuration. Thefilaments 716 can also be texturized by crimping, coiling, etc. When theweft yarns 714 are in a relaxed, non-tensioned state, the filaments 716can be loosely packed and can provide compressible volume or bulk to thefabric, as well as a plush surface. In some embodiments, the weft yarns714 can have a denier of from about 1 D to about 500 D, about 10 D toabout 400 D, about 20 D to about 350 D, about 20 D to about 300 D, orabout 40 D to about 200 D. In certain embodiments, the weft yarns 714can have a denier of about 150 D. In some embodiments, a filament countof the weft yarns 714 can be from 2 filaments per yarn to 200 filamentsper yarn, 10 filaments per yarn to 100 filaments per yarn, 20 filamentsper yarn to 80 filaments per yarn, or about 30 filaments per yarn to 60filaments per yarn. Additionally, although the axially-extendingtextured yarns 714 are referred to as weft yarns in the illustratedconfiguration, the fabric may also be manufactured such that theaxially-extending textured yarns are warp yarns and thecircumferentially-extending yarns are weft yarns.

FIGS. 40A and 40B illustrate a cross-sectional view of the main layer702 in which the weft yarns 712 extend into the plane of the page. Withreference to FIG. 40A, the fabric of the main layer 702 can have athickness t₂ of from about 0.1 mm to about 10 mm, about 1 mm to about 8mm, about 1 mm to about 5 mm, about 1 mm to about 3 mm, about 0.5 mm,about 1 mm, about 1.5 mm, about 2 mm, about 2.5 mm, or about 3 mm whenin a relaxed state and secured to a frame. In some embodiments, the mainlayer 702 can have a thickness of about 0.1 mm, about 0.2 mm, about 0.3mm, about 0.4 mm, or about 0.5 mm as measured in a relaxed state with aweighted drop gauge having a presser foot. In a representative example,the main layer 702 can have a thickness of about 1.5 mm when secured toa prosthetic valve frame in the relaxed state. This can allow the fabricof the main layer 702 to cushion the leaflets between the valve body andan anchor or ring into which the valve is implanted, as well as tooccupy voids or space in the anatomy. The texturized, loosely packedfilaments 716 of the weft yarns 714 in the relaxed state can alsopromote tissue growth into the main layer 702.

When the fabric is in the relaxed state, the textured filaments 716 ofthe weft yarns 714 can be widely dispersed such that individual weftyarns are not readily discerned, as in FIGS. 38A and 38B. Whentensioned, the filaments 716 of the weft yarns 714 can be drawn togetheras the weft yarns elongate and the kinks, twists, etc., of the filamentsare pulled straight such that the fabric is stretched and the thicknessdecreases. In certain embodiments, when sufficient tension is applied tothe fabric in the axial (e.g., weft) direction, such as when theprosthetic valve is crimped onto a delivery shaft, the textured fibers716 can be pulled together such that individual weft yarns 714 becomediscernable, as best shown in FIGS. 39B and 40B.

Thus, for example, when fully stretched, the main layer 702 can have asecond thickness t₃, as shown in FIG. 40B that is less than thethickness t₂. In certain embodiments, the thickness of the tensionedweft yarns 714 may be the same or nearly the same as the thickness ti ofthe warp yarns 712. Thus, in certain examples, when stretched the fabriccan have a thickness t₃ that is the same or nearly the same as threetimes the thickness t₁ of the warp yarns 712 depending upon, forexample, the amount of flattening of the weft yarns 714. Accordingly, inthe example above in which the warp yarns 712 have a thickness of about0.06 mm, the thickness of the main layer 702 can vary between about 0.2mm and about 1.5 mm as the fabric stretches and relaxes. Stateddifferently, the thickness of the fabric can vary by 750% or more as thefabric stretches and relaxes.

Additionally, as shown in FIG. 40A, the warp yarns 712 can be spacedapart from each other in the fabric by a distance y₁ when the outercovering is in a relaxed state. As shown in FIGS. 39B and 40B, whentension is applied to the fabric in the direction perpendicular to thewarp yarns 712 and parallel to the weft yarns 714, the distance betweenthe warp yarns 712 can increase as the weft yarns 714 lengthen. In theexample illustrated in FIG. 40B, in which the fabric has been stretchedsuch that the weft yarns 714 have lengthened and narrowed toapproximately the diameter of the warp yarns 712, the distance betweenthe warp yarns 712 can increase to a new distance y₂ that is greaterthan the distance y₁.

In certain embodiments, the distance y₁ can be, for example, about 1 mmto about 10 mm, about 2 mm to about 8 mm, or about 3 mm to about 5 mm.In a representative example, the distance y₁ can be about 3 mm. In someembodiments, when the fabric is stretched as in FIGS. 39B and 40B, thedistance y₂ can be about 6 mm to about 10 mm. Thus, in certainembodiments, the length of the outer covering 700 can vary by 100% ormore between the relaxed length L₁ and the fully stretched length (e.g.,L₂). The fabric's ability to lengthen in this manner can allow theprosthetic valve to be crimped to diameters of, for example, 23 Fr,without being limited by the outer covering's ability to stretch. Thus,the outer covering 700 can be soft and voluminous when the prostheticvalve is expanded to its functional size, and relatively thin when theprosthetic valve is crimped to minimize the overall crimp profile of theprosthetic valve.

FIGS. 41A, 41B, 42A, and 42B show an outer sealing member or covering800 for a prosthetic heart valve (e.g., such as the prosthetic heartvalve 400), according to another embodiment. The sealing member 800 canbe a dual-layer fabric comprising a base layer 802 and a pile layer 804.FIG. 41A shows the outer surface of the sealing member 800 defined bythe pile layer 804. FIG. 42A shows the inner surface of the sealingmember 800 defined by the base layer 802. The base layer 802 in theillustrated configuration comprises a mesh weave havingcircumferentially extending rows or stripes 806 of higher-density meshportions interspersed with rows or stripes 808 of lower-density meshportions.

In particular embodiments, the yarn count of yarns extending in thecircumferential direction (side-to-side or horizontally in FIGS. 42A and42B) is greater in the higher-density rows 806 than in the lower-densityrows 808. In other embodiments, the yarn count of yarns extending in thecircumferential direction and the yarn count of yarns extending in theaxial direction (vertically in FIGS. 42A and 42B) is greater in thehigher-density rows 806 than in the lower-density rows 808.

The pile layer 804 can be formed from yarns woven into the base layer802. For example, the pile layer 804 can comprise a velour weave formedfrom yarns incorporated in the base layer 802. Referring to FIG. 41B,the pile layer 804 can comprise circumferentially extending rows orstripes 810 of pile formed at axially-spaced locations along the heightof the sealing member 800 such that there are axial extending gapsbetween adjacent rows 810. In this manner, the density of the pile layervaries along the height of the sealing member. In alternativeembodiments, the pile layer 804 can be formed without gaps betweenadjacent rows of pile, but the pile layer can comprise circumferentiallyextending rows or stripes of higher-density pile interspersed with rowsor stripes of lower-density pile.

In alternative embodiments, the base layer 802 can comprise a uniformmesh weave (the density of the weave pattern is uniform) and the pilelayer 804 has a varying density.

In alternative embodiments, the density of the sealing member 800 canvary along the circumference of the sealing member. For example, thepile layer 804 can comprise a plurality of axially-extending,circumferentially-spaced, rows of pile yarns, or alternatively,alternating axially-extending rows of higher-density pile interspersedwith axially-extending rows of lower-density pile. Similarly, the baselayer 802 can comprise a plurality axially-extending rows ofhigher-density mesh interspersed with rows of lower-density mesh.

In other embodiments, the sealing member 800 can include a base layer802 and/or a pile layer 804 that varies in density along thecircumference of the sealing member and along the height of the sealingmember.

Varying the density of the pile layer 804 and/or the base layer 802along the height and/or the circumference of the sealing member 800 isadvantageous in that it reduces the bulkiness of the sealing member inthe radially collapsed state and therefore reduces the overall crimpprofile of the prosthetic heart valve.

In certain embodiments, the outer covering 800 can include inflow and/oroutflow protective portions similar to the protective portions 416 and418 above. However, in other embodiments, the outer covering 800 neednot include protective portions and can extend between the top andbottom row of strut members of a frame, or between intermediate rows ofstrut members, depending upon the particular application.

Although the prosthetic valve covering embodiments described herein arepresented in the context of mitral valve repair, it should be understoodthat the disclosed coverings can be used in combination with any ofvarious prosthetic heart valves for implantation at any of the valves inthe heart. For example, the prosthetic valve coverings described hereincan be used in combination with transcatheter heart valves, surgicalheart valves, minimally-invasive heart valves, etc. The coveringembodiments can be used in valves intended for implantation at any ofthe native annuluses of the heart (e.g., the aortic, pulmonary, mitral,and tricuspid annuluses), and include valves that are intended forimplantation within existing prosthetics valves (so called“valve-in-valve” procedures). The covering embodiments can also be usedin combination with other types of devices implantable within other bodylumens outside of the heart, or heart valves that are implantable withinthe heart at locations other than the native valves, such astrans-atrial or trans-ventricle septum valves.

General Considerations

For purposes of this description, certain aspects, advantages, and novelfeatures of the embodiments of this disclosure are described herein. Thedisclosed methods, apparatus, and systems should not be construed asbeing limiting in any way. Instead, the present disclosure is directedtoward all novel and nonobvious features and aspects of the variousdisclosed embodiments, alone and in various combinations andsub-combinations with one another. The methods, apparatus, and systemsare not limited to any specific aspect or feature or combinationthereof, nor do the disclosed embodiments require that any one or morespecific advantages be present or problems be solved.

Although the operations of some of the disclosed embodiments aredescribed in a particular, sequential order for convenient presentation,it should be understood that this manner of description encompassesrearrangement, unless a particular ordering is required by specificlanguage set forth below. For example, operations described sequentiallymay in some cases be rearranged or performed concurrently. Moreover, forthe sake of simplicity, the attached figures may not show the variousways in which the disclosed methods can be used in conjunction withother methods. Additionally, the description sometimes uses terms like“provide” or “achieve” to describe the disclosed methods. These termsare high-level abstractions of the actual operations that are performed.The actual operations that correspond to these terms may vary dependingon the particular implementation and are readily discernible by one ofordinary skill in the art.

As used in this application and in the claims, the singular forms “a,”“an,” and “the” include the plural forms unless the context clearlydictates otherwise. Additionally, the term “includes” means “comprises.”Further, the terms “coupled” and “associated” generally meanelectrically, electromagnetically, and/or physically (e.g., mechanicallyor chemically) coupled or linked and does not exclude the presence ofintermediate elements between the coupled or associated items absentspecific contrary language.

In the context of the present application, the terms “lower” and “upper”are used interchangeably with the terms “inflow” and “outflow”,respectively. Thus, for example, the lower end of the valve is itsinflow end and the upper end of the valve is its outflow end.

As used herein, the term “proximal” refers to a position, direction, orportion of a device that is closer to the user and further away from theimplantation site. As used herein, the term “distal” refers to aposition, direction, or portion of a device that is further away fromthe user and closer to the implantation site. Thus, for example,proximal motion of a device is motion of the device toward the user,while distal motion of the device is motion of the device away from theuser. The terms “longitudinal” and “axial” refer to an axis extending inthe proximal and distal directions, unless otherwise expressly defined.

In view of the many possible embodiments to which the principles of thedisclosed technology may be applied, it should be recognized that theillustrated embodiments are only preferred examples and should not betaken as limiting the scope of the disclosure. Rather, the scope of thedisclosure is at least as broad as the following claims.

What is claimed is:
 1. A prosthetic heart valve, comprising: a framecomprising a plurality of strut members, and having an inflow end and anoutflow end; a leaflet structure situated at least partially within theframe; and a covering disposed around an exterior of the frame, thecovering comprising: a cushioning layer; a first strip member foldedover an inflow circumferential edge portion of the cushioning layer toform a first protective portion; and a second strip member folded overan outflow circumferential edge portion of the cushioning layer to forma second protective portion; wherein the first strip member and thesecond strip member are spaced apart from each other along alongitudinal axis of the prosthetic heart valve.
 2. The prosthetic heartvalve of claim 1, wherein the cushioning layer forms an exterior surfaceof the covering.
 3. The prosthetic heart valve of claim 1, wherein: thecushioning layer comprises a first material; and the first strip membercomprises a second material different from the first material.
 4. Theprosthetic heart valve of claim 3, wherein the first material is a wovenfabric, and the second material is a polymeric material or a tissuematerial.
 5. The prosthetic heart valve of claim 4, wherein the wovenfabric of the cushioning layer comprises texturized yarns that providecompressible volume to the woven fabric.
 6. The prosthetic heart valveof claim 5, wherein the woven fabric of the cushioning layer isstretchable between a first configuration corresponding to a radiallyexpanded configuration of the prosthetic heart valve and a secondconfiguration corresponding to a radially collapsed configuration of theprosthetic heart valve.
 7. The prosthetic heart valve of claim 6,wherein a thickness of the woven fabric of the cushioning layer isgreater when the prosthetic heart valve is in the expanded configurationthan when the prosthetic heart valve is in the collapsed configuration.8. The prosthetic heart valve of claim 4, wherein the first material ofthe cushioning layer comprises woven polyethylene terephthalate (PET)fabric, and the second material of the first strip member comprisesexpanded polytetrafluoroethylene (ePTFE).
 9. The prosthetic heart valveof claim 1, wherein the first strip member extends around acircumference of the inflow end of the frame, and the second stripmember extends around a circumference of the outflow end of the frame.10. The prosthetic heart valve of claim 1, wherein the first stripmember extends over inflow apices of the frame, and the second stripmember extends over outflow apices of the frame.
 11. The prostheticheart valve of claim 1, wherein: the first strip member comprises afirst circumferential edge portion and a second circumferential edgeportion; and the first circumferential edge portion is disposed outsidethe frame, and the second circumferential edge portion is disposedinside the frame.
 12. The prosthetic heart valve of claim 11, whereinthe first and second circumferential edge portions of the first stripmember are sutured together through the cushioning layer to form thefirst protective portion.
 13. The prosthetic heart valve of claim 12,wherein: the prosthetic heart valve further comprises an inner skirtdisposed within the frame; and the first strip member is sutured to theinner skirt.
 14. A prosthetic heart valve, comprising: a framecomprising a plurality of strut members, and having an inflow end and anoutflow end; a leaflet structure situated at least partially within theframe; and a covering disposed around an exterior of the frame, thecovering comprising: a cushioning layer comprising a first material, thecushioning layer forming an exterior surface of the covering; and afirst protective portion at the inflow end of the frame, the firstprotective portion comprising a second material different from the firstmaterial; and a second protective portion at the outflow end of theframe, the second protective portion comprising the second material. 15.The prosthetic heart valve of claim 14, wherein the cushioning layercomprises a woven fabric including texturized yarns that providecompressible volume to the woven fabric.
 16. The prosthetic heart valveof claim 15, wherein the cushioning layer comprises polyethyleneterephthalate (PET).
 17. The prosthetic heart valve of claim 14, whereinthe first protective portion comprises a first strip member comprisingthe second material, the first strip member being folded over an inflowcircumferential edge portion of the cushioning layer to form the firstprotective portion.
 18. The prosthetic heart valve of claim 17, whereinthe second material comprises expanded polytetrafluoroethylene (ePTFE).19. The prosthetic heart valve of claim 14, wherein the first protectiveportion and the second protective portion are spaced apart from eachother along a longitudinal axis of the prosthetic heart valve.
 20. Aprosthetic heart valve, comprising: a frame comprising a plurality ofstrut members, and having an inflow end and an outflow end; a leafletstructure situated at least partially within the frame; and a coveringdisposed around an exterior of the frame, the covering comprising: acushioning layer comprising a woven fabric; a first strip member foldedover an inflow circumferential edge portion of the cushioning layer toform a first protective portion, the first strip member comprisingexpanded polytetrafluoroethylene (ePTFE); and a second strip memberfolded over an outflow circumferential edge portion of the cushioninglayer to form a second protective portion, the second strip membercomprising ePTFE; wherein the first strip member and the second stripmember are spaced apart from each other along a longitudinal axis of theprosthetic heart valve.